The human heart is a very complex organ, which relies on both muscle contraction and electrical impulses to function properly. The electrical impulses travel through the heart walls, first through the atria and then the ventricles, causing the corresponding muscle tissue in the atria and ventricles to contract. Thus, the atria contract first, followed by the ventricles. This order is essential for proper functioning of the heart. The coronary sinus is a collection of veins joined together to form a large vessel that collects blood from the myocardium of the heart. It delivers deoxygenated blood to the right atrium in conjunction with the superior and inferior vena cava. The coronary sinus opens into the right atrium, between the inferior vena cava and the auriculo-ventricular opening. It returns the blood from the heart, and is protected by a semicircular fold of the lining membrane of the auricle, the coronary valve.
An indwelling positioned coronary sinus catheter is used as a reference site for electrophysiology studies due to its tubular shape and anatomical positioning on the atrioventricular groove (AV) groove. Catheters are inserted into the coronary sinus ostium and advanced distally to provide both left sided (most distal) and right sided (most proximal) signals. Because the coronary sinus is located in the AV groove, the signals uniquely show both atrial and ventricular activity. The current state of the art CS catheter uses ten (10) poles for recording signals throughout the coronary sinus. Because these catheters are stationary they make a good choice for a timing reference when performing a mapping procedure while a second or third catheter is in the chambers of the heart. They are also used as location or position references with 3D mapping systems such as Velocity™, NAVX™ sold by St. Jude Medical or the CARTO XP and CARTO3 systems sold by BioSense-Webster division of Johnson and Johnson.
Unfortunately, current coronary sinus catheters suffer from a number of disadvantages and in particular, physicians have reported that the coronary sinus catheter can move during the electrophysiology procedure and, when it does, there will be a change in the reference signal. This creates inaccuracies in maps and makes comparisons from one map to another very difficult. There is therefore a need for an improved coronary sinus catheter that overcomes the disadvantages associated with the conventional coronary sinus catheter.